/// <summary> Shows the building menu (see <see cref="buildingMenuPrefab"/>) at the same
/// screen position as the parameter LymphNode <paramref name="lymphNode"/>. Called by a
/// LymphNode object when it is clicked without a tower on it. </summary>
internal GameObject ShowBuildingMenu(Transform lymphNode)
{
GameObject buildingMenu = Instantiate(buildingMenuPrefab, new Vector3(0f, 0f, -1.2f), activeGameUIPanel.rotation);
buildingMenu.transform.SetParent(activeGameUIPanel, false);
/////////////////////////////////////
// gather the cost data
// todo: the building menu should dim towers that are unavailable for whatever reason
ShopMenu shopMenu = buildingMenu.GetComponent <ShopMenu>();
Shop shop = Shop.instance;
if (shopMenu != null)
{
int cost1 = -1;
int cost2 = -1;
int cost3 = -1;
int cost4 = -1;
if (shop.tower1 != null)
{
cost1 = shop.tower1.GetBaseLevelCost();
}
if (shop.tower2 != null)
{
cost2 = shop.tower2.GetBaseLevelCost();
}
if (shop.tower3 != null)
{
cost3 = shop.tower3.GetBaseLevelCost();
}
if (shop.tower4 != null)
{
cost4 = shop.tower4.GetBaseLevelCost();
}
shopMenu.SetCostTower1(cost1);
shopMenu.SetCostTower2(cost2);
shopMenu.SetCostTower3(cost3);
shopMenu.SetCostTower4(cost4);
}
/////////////////////////////////////
// UI elements and other scene objects use different coordinate systems;
// in order to position the menu where the lymph node is (on the screen)...
// ...we have to do some conversions between World and Viewport
RectTransform buildingMenuRT = buildingMenu.GetComponent <RectTransform>();
RectTransform canvasRT = activeGameUIPanel.parent.GetComponent <RectTransform>(); // this assumes that this panel is the child of the top-level UI panel
Vector2 viewportPosition = Camera.main.WorldToViewportPoint(lymphNode.position);
Vector2 uiOffset = new Vector2((float)canvasRT.sizeDelta.x / 2f, (float)canvasRT.sizeDelta.y / 2f); // screen offset for the canvas
Vector2 proportionalPosition = new Vector2(viewportPosition.x * canvasRT.sizeDelta.x, viewportPosition.y * canvasRT.sizeDelta.y); // position on the canvas
// set the position and remove the screen offset
buildingMenuRT.localPosition = proportionalPosition - uiOffset;
return(buildingMenu);
}